Ultra-Lightweight Proppants in Shale Gas Fracturing

Abstract

Abstract The goal of the present work is to evaluate ultra light weight proppants for fracturing of shale gas reservoirs. Three ultra light weight proppants (ULW-1, ULW-2, and ULW-3) have been studied. The mechanical properties of the proppant packs as well as single proppants have been measured. Conductivity of proppant packs has been determined as a function of proppant concentration, confining stress, and temperature. The crush strengths of all the three proppant packs are higher than typical stresses encountered in the Barnett shale. ULW-1 and ULW-2 are highly deformable and do not produce many fines. ULW-3 has a higher Young's modulus and produces fines. The proppant conductivity decreases with increasing confining stress, but it is not a strong function of the proppant concentration for bothe ULW-1 and ULW-2. A partial monolayer of ULW-2 (0.07 lbm/ft2) provides slightly less or as much conductivity as a thick proppant pack with a concentration of 0.7 lbm/ft2. At 6000 psi stress, the conductivity of ULW-1 seems to decrease a little as the proppant concentration increases and then increases. Application of light weight proppants in stimulation treatments in shale reservoirs can lead to long propped fractures, which can improve the productivity of fractured shale reservoirs.